AFAIK there is no scheduled Boeing 767 service into LGA. They venture into little laguardia when they need to substitute equipment or as you stated @Deltajets.
DL used to fly light Boeing 767-400ERs from ATL-LGA-ATL and even earlier, L-1011s.
UA, AA, CO, and PA all flew DC-10s into LGA. UA flew their DC-10s to DEN and ORD (Not 100% sure about ORD). DL probably flew DC-10s into LGA at some point.
EA flew TriStars into LGA and MAYBE flew A300s into LGA.
If you want, go google some more pics of DC-10s at LGA but UA and AA are the first two to pop to mind.
Now that I said everything above, since we have seen the majestic and huge DC-10 at LGA, that goes to show how rare the 767 is at LGA because it is even bigger than the DC-10.
SO DON’T FLY ANY 747s, 777s, OR A380s INTO LGA!!!